1. Field of the Invention
The present invention relates to an ink supply device and a recording head of an ink-jet recording apparatus for discharging flying liquid drops of ink as a recording liquid as ink droplets from a discharge port to perform recording on recording paper, more concretely to an ink supply device which is provided with a removing device for removing dust, and to a recording head.
2. Description of the Related Art
In an ink-jet recording head, it is constructed so as to supply ink to a common chamber communicating with a discharge port, in which a filter device having a filter for preventing contamination with fine dust or the like which may be a cause of nozzle clogging is provided in a passage for introducing the ink supplied from an ink tank. Such filter device is generally of a type in which a filter box is connected to a pipe for introducing the ink. A filter is disposed in the filter box, and the diameter of the filter is normally larger than the diameter of the pipe. For this reason, an inside diameter of the pipe in the vicinity of the filter is increased towards the filter diameter, resulting in a bell-bottomed shape of the pipe of this portion.
However, if an expanded portion of a flow passage such as a bell-bottomed portion is present in a filter device of an ink supply device, the ink flow rate is decreased at this portion resulting in a stagnation of the ink, and a bubble is liable to generate in the vicinity of the filter. Further, a once-generated bubble does not readily disappear but tends to adhere to the filter. As a result, an effective area of the filter is decreased, which may disturb an ink refill, leading to an unstable discharge or a discharge failure due to an insufficient ink refill.